SUBFAMILIES, GENERA, AND SPECIES
Each one of these four families is divided into several subfamilies; each subfamily is divided into several genera, and each genus is divided into several species, all of these divisions being based on an increasing anatomical similarity. Thus the common Milkweed Butterfly belongs to the class Insecta, the order Lepidoptera, the suborder Rhopalocera, the family Nymphalidae, the subfamily Euploeinae, the genus Anosia, and the species Plexippus.